1. Field
The present invention relates to a video signal processing device which removes a dot interference signal component mixed in a luminance signal and a cross color signal component mixed in a color signal, the luminance signal and the color signal being obtained by separating the video signal.
2. Description of the Related Art
In a composite vide signal of a standard television system such as an NTSC system or a PAL system, luminance and color signals are multiplexed, and a composite signal input to a display device such as a television is separated into a luminance signal and a color signal. During this separation process, unless the separation is complete, the color signal is mixed (left) in the luminance signal, and the luminance signal is mixed in the color signal. The color signal mixed in the luminance signal is called a dot interference signal, and the luminance signal mixed in the color signal is called a cross color signal. These dot interference and cross color signals greatly reduce quality of the video signal.
In a digital broadcast that has recently gained in popularity, such a phenomenon occurs. For example, when content recorded in an analog signal form is digitized to be broadcast, the broadcast digital signal itself may contain a dot interference signal or a cross color signal. Even when such a digital video signal is received to be converted into an analog video signal, a dot interference signal or a cross color signal is contained in the converted analog video signal.
Jpn. Pat. Appln. KOKAI Publication No. 2004-128936 discloses a device for removing a cross color signal from a color signal. The cross color removing device described in this Publication is configured in such a manner that it executes moving image/static image determination based on a difference between frames of luminance signals, and a cross color removing circuit is operated only when a static image is determined. According to this configuration, the cross color removing circuit takes only two states, i.e., operated and unoperated states. Consequently, there has been a problem of impossibility of executing fine control in accordance with an amount of motion.